Legalism isn't bound just to the south. I was born a yankee (hillbilly by choice!) and there were legalistic churches up there too. They just didn't survive as well as the southern ones did.
We moved south in 1974 and the folks down here hadn't even heard of the Sword of the Lord. However, in Michigan all the church folks I knew read it. But at that time, as John has stated, the Sword was a very different publication. (take it from someone who grew up reading it)
Legalism starts in the congregation. It is individuals who push it along and vote for a fire breathing, shouting, spitting preacher that says you must not be a Christian if you...... I didn't hear that stuff first from church. I heard it from my parents. It was they who said you can't: go to movies, say gosh, golly, darn, smoke tobacco, play cards (even have a deck in your house!), dance, drink alcohol, wear shorts(though the same didn't apply to my brother), read Darwin, or use a Bible that didn't have KJV stamped on it: doing so would send my poor young soul straight to hell!
Imagine my surprise when we moved south and lo and behold the DEACONS smoked out on the church steps in between Sunday school and the sermon!
Boy oh boy did my parents have some explaining to do!
Those sorts of things didn't become a big deal at church until I was a teen long about 1980, maybe a bit before. What church? Why the Freewill Baptist church we attended at the time. All that skirts only stuff even when you weren't at church, well, members who didn't agree, just ignored it.
It wasn't until after this that the SOTL really changed into something I no longer recognized. So far it hasn't changed back but its better than in the days when it was a constant criticism of everyone who didn't follow the leader (especially the SBC).
It seems to me that IFB has become a catchall phrase for the condemnation of those congregations who stress congregational standards over soul liberty, who have become highly patriarchal/elder/pastor led (with little to no female leadership), but who are identified mostly by their long-haired, skirt wearing, husband dominated women folk!
What many fail to realize is that congregations, who stress congregational standards over soul liberty, who have become highly patriarchal/elder/pastor led (with little to no female leadership), but who are identified mostly by their long-haired, skirt wearing, husband dominated women folk, aren't limited to the Baptist faith in general much less IFBs. They are scattered all over every denomination.
We need to get away from the IFB label and call these folk what they are: MFC's (Misguided, Fundmental leaning, Churches).
See?